Pressure-cutoff arrangement for an auxiliary power steering system in the end positions of the steering lock

Abstract

The invention relates to a pressure-cutoff arrangement for an auxiliary power steering system in the end positions of the steering lock, having at least one working poston 2 which is displaceable in the axial direction in a steering housing 1 and delimits two working spaces I, II, cutoff valves 7, 17 associated with the working piston 2, and also stop elements 13, 23 which are associated with the steering housing 1 and are displaceable in the axial direction and against which one of the cutoff valves 7, 17 runs, in each case, in the end position and, in doing so, opens for the purpose of cutting off the pressure, and wherein the stop elements 13, 23 are fixed in a force-locking manner, with a retaining force which exceeds the opening force of the cutoff valves 7, 17, a spring 14, 24 acting in the radial direction.

What is claimed is:  
     
       1. Pressure-cutoff arrangement for an auxiliary power steering system in the end positions of the steering lock, wherein the auxiliary power steering system has at least one working piston ( 2 ) which is displaceable in the axial direction in a steering housing ( 1 ) and delimits two working spaces (I, II), cutoff valves ( 7 ,  17 ) associated with the said working piston ( 2 ), and also stop means ( 13 ,  23 ) which are associated with the steering housing ( 1 ) and are displaceable in the axial direction and against which one of the cutoff valves ( 7 ,  17 ) runs, in each case, in the end position and, in doing so, opens for the purpose of cutting off the pressure, characterised in that the stop means ( 13 ,  23 ) are fixed in a force-locking manner, with a retaining force which exceeds an opening force of the cutoff valves ( 7 ,  17 ), by means of a spring ( 14 ,  24 ) acting in the radial direction. 
     
     
       2. Device according to claim  1 , characterised in that the stop means ( 13 ,  23 ) has an essentially round shaft region, and that the spring ( 14 ,  24 ) surrounds the said shaft region in the form of a ring. 
     
     
       3. Device according to claim  1 , characterised in that the spring ( 14 ,  24 ) is a circumferential coil spring with a wave-like profile ( 30 ) in the peripheral direction. 
     
     
       4. Device according claim  1 , characterised in that the stop means ( 13 ,  23 ) are guided, in each case, in a bore ( 11 ,  21 ), each bore ( 11 ,  21 ) having a removable fluid-tight and pressure-tight closure ( 15 ,  26 ), after the removal of which, one end of the particular stop means ( 13 ,  23 ), which end faces away from the working piston ( 2 ) of the steering housing ( 1 ), is accessible. 
     
     
       5. Device according to claim  4 , characterised in that the bore ( 21 ) is a through-bore in the steering housing ( 1 ). 
     
     
       6. Device according to claim  4 , characterised in that the bore ( 11 ) is a blind bore or a through-bore in a hollow screw, which is to be fastened separately in the steering housing ( 1 ). 
     
     
       7. Device according to claim  1 , characterised in that the spring ( 14 ,  24 ) is enclosed, and fixed in the axial direction, in an annular groove associated with the bore ( 11 ,  21 ) or a shaft region.